JPH10161664A - Active vibration suppressing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an active vibration suppressing device in which control performance can be improved even when the number of reference signals is increased. SOLUTION: The signals from vibration detectors 1-5 detecting the vibration from a vibrating source are taken as reference signals, and the reference signals are converted into mutually non-correlative main component signals by a main component converting circuit 9. The converted main component signals and the output signal from a microphone 8 are inputted to an adaptive control circuit 6, a cancel signal for canceling the vibration by the vibrating source is generated in the adaptive control circuit 6, and a speaker 7 is driven by the cancel signal. The difference between the output sound from the speaker 7 and the vibration by the vibrating source is detected by the microphone 8, and the adaptive parameter contained in the adaptive control circuit is changed on the basis of the difference signal detected by the microphone 8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an active vibration suppressing device for canceling noise based on vibration from a vibration source by output sound from a canceling vibration generating device.

[0002]

2. Description of the Related Art In this specification, the term "vibration" is used to include "noise".

[0003] As an example of a case in which an active vibration suppression device is applied to a vehicle, as one of measures against vehicle interior vibration, active vibration that generates vibration in a phase opposite to that of the vehicle interior to cancel the vibration in the vehicle interior. Suppression device (hereinafter also referred to as “AVNC”)
It has been known.

In such a conventional active vibration suppressing device, vibration from a vibration source is detected by a vibration detector, and a signal based on the vibration detected by the vibration detector is input as a reference signal, and the vehicle interior is calibrated based on the reference signal. The adaptive control circuit generates a cancellation signal having a phase opposite to that of the vibration of the vehicle, detects a difference between the cancellation vibration generated based on the generated cancellation signal, and the vibration in the vehicle cabin based on the vibration source, and based on the difference. There is one in which a difference signal is transmitted, and an adaptive parameter included in an adaptive control circuit is changed based on the difference signal.

The conventional active vibration suppressing device described above specifically detects vibration of an engine mounted on a vehicle 10 by a vibration detector 1 and converts the vibration into an electric signal as shown in FIG. The vibration of the suspension that suspends the wheels is detected by the vibration detectors 2 to 5 and converted into electric signals, the electric signals output from the vibration detectors 1 to 5 are used as reference signals, and the reference signals are converted into digital data. Then, the reference signal converted into digital data is supplied to an adaptive control circuit 61 composed of an FIR adaptive digital filter including a filter coefficient variable FIR digital filter and an adaptive algorithm operation unit, and an FIR as an adaptive control output. The output of the adaptive digital filter is converted into an analog signal, and the converted analog signal is provided in the passenger compartment to generate a canceling vibration sound. To drive the speaker 7.

On the other hand, a difference signal which is a difference between the vibration generated in the vehicle cabin by the vibration source of the vehicle 10 and the canceling vibration generated by the speaker 7 is transmitted to a microphone 8 provided in the vehicle cabin.
, And the output signal from the microphone 8 is converted into digital data.
The calculation of the adaptive parameter that minimizes the expected value) is performed in the adaptive algorithm calculation unit of the adaptive control circuit 61, and the filter coefficient of the FIR digital filter is corrected to a filter coefficient based on the calculated value, thereby generating in the vehicle cabin. Vibration is suppressed.

[0007]

In the above-mentioned conventional active vibration suppressing device, the vibration of the vibration source is detected by a vibration detector, and all the detected signals are supplied to a control circuit as reference signals. An arithmetic process is performed to generate a cancellation signal for canceling vibration.

However, when the number of vibration sources for which vibration is to be detected by the vibration detector increases, the number of detection signals increases, and the amount of calculation for generating a cancellation signal in the control circuit increases. For this reason, a calculation time is required, and it takes time until the vibration is suppressed, and there is a problem that the vibration suppression performance of the active vibration suppression device is reduced.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems and to provide an active vibration suppressing device capable of improving control performance even when the number of vibration sources is large.

[0010]

According to the present invention, there is provided an active vibration suppressing apparatus comprising: a vibration detecting means for detecting vibration from a vibration source; and a signal based on the vibration detected by the vibration detecting means, which is input as a reference signal; And a principal component analyzing means for converting the reference signal into a principal component signal which is substantially orthogonal to each other, a canceling vibration generating means, and the principal component signal is input to generate a canceling signal for canceling the vibration from the vibration source, And a control circuit for driving the canceling vibration generating means based on the canceling signal.

In the active vibration suppressing apparatus of the present invention, the vibration of the vibration source is detected by the vibration detecting means, a signal based on the vibration is used as a reference signal, and the principal signal analyzing means makes the reference signals substantially orthogonal to each other. It is converted into a component signal. The converted main component signal is input to the control circuit, and the control circuit generates a canceling signal for canceling the vibration from the vibration source, and the canceling vibration based on the canceling signal is generated by the canceling vibration generating means. The canceling vibration generating means is driven based on the vibration, the vibration from the vibration source is canceled, and the vibration is suppressed.

However, according to the active vibration suppression device of the present invention, the reference signal is converted into a principal component signal orthogonal to each other, and the vibration suppression control is performed based on the principal component signal.
As a result, since the highly correlated reference signal has been removed,
The number of signals input to the control circuit for the vibration suppression control is reduced, the calculation for the vibration suppression control is performed at high speed, and the vibration suppression performance is improved.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an active vibration suppressing device according to the present invention will be described with reference to embodiments.

FIG. 1 is a block diagram showing a configuration of an active vibration suppressing device according to an embodiment of the present invention. The active vibration suppressing device according to the embodiment of the present invention shown in FIG. 1 illustrates a case where the active vibration suppressing device is adapted to a vehicle and suppresses vibration in a vehicle interior.

In the active vibration suppressing device according to one embodiment of the present invention, the vibration of the engine mounted on the vehicle 10 is detected by the vibration detector 1 and converted into an electric signal.
The vibrations of the suspension that suspends the front, rear, left and right wheels are detected by the vibration detectors 2 to 5 and converted into electric signals, and the electric signals output from the vibration detectors 1 to 5 are used as reference signals,
The reference signal is converted to digital data, and the converted reference signal is supplied to a principal component analysis circuit 9 and is converted into a principal component signal orthogonal to each other in a time domain.

The principal component signal converted in the principal component analysis circuit 9 is supplied to an adaptive control circuit 6 composed of an FIR adaptive digital filter comprising a filter coefficient variable FIR digital filter and an adaptive algorithm operation unit, and adaptive control is performed. The output of the FIR adaptive digital filter, which is the output, is converted into an analog signal, and the converted analog signal drives a speaker 7 provided in the vehicle compartment to generate canceling vibration noise.

On the other hand, a difference signal which is a difference between the vibration generated in the vehicle interior by the vibration source of the vehicle 10 and the canceling vibration generated by the speaker 7 is transmitted to the microphone 8 provided in the vehicle interior.
, An output signal from the microphone 8 is converted into digital data, an adaptive parameter operation that minimizes the expected value of the square of the difference signal is calculated in an adaptive algorithm calculation unit, and a filter based on the calculated adaptive parameter is calculated. By correcting the filter coefficient of the FIR digital filter to the coefficient, the vibration generated in the vehicle interior is suppressed.

In the case of active vibration suppression, a case where the principal component analysis circuit 9 of the present invention is not provided will be described first. From the output signals from the vibration detectors 1 to 5, that is, the reference signal and the response of the vehicle interior sound, a transfer function therebetween, that is, a transfer function of the adaptive control circuit is obtained. The adaptive control by the adaptive control circuit assumes that the vibration in the cabin due to the vibration of the vibration source can be approximated by an FIR digital filter, and estimates the parameters of the unknown system by the adaptive control circuit to obtain the same vibration in the cabin as the unknown system. It is to try.

Here, when (R) is a correlation function matrix of the reference signal, (P) is a cross-correlation function vector of a response between the reference signal and the vibration in the vehicle compartment, and (W) is a transfer function, Has the relationship of the following equation (1). Hereinafter, (R), (P), (W), (U), (X)
Etc. represent a matrix.

(R) (W) = (P) (1) By solving the above equation (1), the transfer function (W) is obtained by the equation (2).

(W) = (R) ⁻¹ (P) (2) In this case, when the correlation between the reference signals is large, the condition number cond of the reference signal correlation function matrix (R)
[R] becomes large, and it becomes difficult to numerically solve the inverse matrix (R) ⁻¹ , and it becomes difficult to calculate the transfer function (W) by the equation (2).

The condition number cond [R] of the reference signal correlation function matrix (R) is the ratio between the maximum singular value σmax and the minimum singular value σmin of the reference signal correlation function matrix (R), and the condition number cond [R ] = Σmax / σmi
n.

However, in the active vibration suppressing device according to one embodiment of the present invention, that is, when the principal component analysis circuit 9 is provided, the reference signal is supplied to the principal component analysis circuit 9 to perform the principal component analysis. Is done. In this case, the number of main component signals can be equal to the number of vibration detectors, that is, “5” in the present embodiment. However, in the active vibration suppression device according to the embodiment of the present invention, the main component signals that are not orthogonal to each other are After being removed, only the principal component signals whose reference signals are orthogonal to each other are supplied by the principal component analysis circuit 9 to the adaptive control circuit 6 as reference signals.

Therefore, the signals supplied to the adaptive control circuit 6 are uncorrelated independent main component signals having no correlation with each other, and the condition number [R] of the reference signal correlation function matrix (R) is reduced, and Matrix (R) ^-1 is numerically easy to solve. As a result, the calculation of the transfer function (W) by the equation (2) becomes easy.

The mathematical processing of the principal component analysis is as shown in the following equation (3), which is equivalent to eigenvalue decomposition.

(R) = (U) (R ′) (U) ^t (3) where (U) is the eigenvector matrix of the correlation function matrix (R) of the reference signal, and (R ′) is the reference The eigenvalue diagonal matrix of the correlation function matrix (R) of the signal, and (U) ^t is the transposed matrix of (U).

Using this eigenvector matrix (U), a principal component signal is obtained as shown in equation (4).
(X) shows a reference acceleration signal matrix, and (X ') shows a main component matrix.

(X) = (U) (X ′) (4) This principal component signal is supplied to the adaptive control circuit 6 as a new reference signal, the load on the transfer function calculation is reduced, and the convergence of the adaptive parameter is achieved. The speed, that is, the convergence speed of the filter coefficient is increased.

Further, by removing unnecessary principal component signals as uncorrelated principal component signals supplied to the adaptive control circuit 6, the number of signals supplied to the adaptive control circuit 6 is reduced, and the amount of calculation is reduced. And the convergence speed of the filter coefficients is increased.

Further, as described above, in the active vibration suppressing device according to the embodiment of the present invention, the principal component analysis is performed in the time domain, and is converted into principal component signals that are substantially orthogonal to each other.

As described above, in the active vibration suppressing device according to the embodiment of the present invention, since the principal component analysis is performed in the time domain, the reference signal correlation function matrix (R),
The order of the eigenvector matrix (U) is (the number of vibration detectors) × (the number of vibration detectors), that is, a matrix of 5 rows × 5 rows, and the calculation amount in the calculations of the equations (3) and (4) is It requires less time and requires less time for calculation.

The small amount of calculation is very effective for suppressing the active vibration because the calculation of equation (4) needs to be performed in real time.

On the other hand, instead of the principal component analysis in the time domain,
It is also possible to perform in the frequency domain. However, when performing the principal component analysis in the frequency domain, the reference signal correlation function matrix (R) and the eigenvector matrix (U)
Is multiplied by the frequency spectrum when the frequency of the reference signal is frequency-analyzed to the order of the matrix in the time domain described above, and the amount of calculation increases, and it takes time to calculate equations (3) and (4). That would be.

Further, in the active vibration suppressing device according to the embodiment of the present invention, since only the main component signal having the correlation is removed, the main component signal output from the main component analysis circuit 9 is used as the main component analysis circuit. 9 is a principal component signal affected by all the reference signals, and retains the information of the reference signal, so that the information amount of the reference signal is not reduced.

[0035]

As described above, according to the active vibration suppressing apparatus of the present invention, the number of signals supplied to the adaptive control circuit is reduced, and the convergence speed of the adaptive parameter is increased.
Furthermore, since the main component signal is an uncorrelated signal, the condition number of the correlation matrix of the reference signal is reduced, and the operation time is shortened and the operation accuracy is improved.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an active vibration suppression device according to an embodiment of the present invention.

FIG. 2 is a block diagram illustrating a configuration of a light emitting and receiving device and a road surface condition recognition unit in the active vibration suppression device according to one embodiment of the present invention.

[Explanation of symbols]

 1-5 Vibration detector 6 Adaptive control circuit 7 Speaker 8 Microphone 9 Principal component analysis circuit 10 Vehicle

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Mitsuru Nakamura 1-4-1 Chuo, Wako-shi, Saitama

Claims (3)

[Claims] 1. A vibration detecting means for detecting a vibration from a vibration source, a signal based on the vibration detected by the vibration detecting means is input as a reference signal, and the reference signal is converted into a principal component signal substantially orthogonal to each other. Principal component analyzing means for converting, Canceling vibration generating means, The main component signal is input to generate a canceling signal for canceling the vibration from the vibration source, and the canceling vibration generating means is driven based on the canceling signal. An active vibration suppression device, comprising: a control circuit configured to: 2. The active vibration suppressing device according to claim 1, wherein the conversion into the principal component signal by the principal component analysis means is performed in a time domain. 3. The active vibration suppressing device according to claim 1, wherein the number of main component signals input to the control circuit is smaller than the number of reference signals.